The reliability and validity of general psychotic rating scales with people with mild and moderate intellectual disabilities: an empirical investigation

Background Whilst assessment tools have been developed to diagnose schizophrenia in people with mild intellectual disabilities (IDs), little attention has been paid to developing reliable and valid dimensional measures of psychotic experiences with this population. This study investigates the reliability and validity of two such measures developed for the general adult psychiatric population, the Positive and Negative Syndrome Scale (PANSS) and the Psychotic Symptom Rating Scales (PSYRATS), with a population of adults with mild IDs. Method Sixty-two adults with mild IDs were interviewed using the PANSS and PSYRATS, and independently interviewed using the Psychiatric Assessment Schedule – Adults with Developmental Disability (PAS-ADD) to obtain psychiatric diagnoses to the criteria of the International Classification of Diseases – Tenth Revision (ICD-10). On the basis of ICD-10 diagnosis, participants were divided into three groups: psychosis (n = 11); other mental health problem (n = 14); no mental health problem (n = 37). PANSS and PSYRATS subscale scores were compared across these three groups and were correlated with PAS-ADD symptom scores across a number of PAS-ADD symptom domains. Results All PANSS and PSYRATS subscales showed adequate internal reliability, largely good test-retest reliability, and logical inter-correlations between subscales. The PANSS positive symptoms and the PSYRATS auditory hallucinations subscales differentiated between the psychosis group and the other groups; the PANSS general symptoms subscale differentiated between the psychosis and no mental health problem groups; and the PANSS negative symptoms and the PSYRATS delusions subscales did not differentiate between the three groups. Conclusions The PANSS and PSYRATS are promising measures for use with people with mild IDs and psychotic experiences, although further investigation of items relating to negative symptoms and delusions is warranted.     

Evaluation eines standardisierten Trainings für die “Positive and Negative Syndrome Scale” (PANSS)

The present analysis comprises 3 studies on the interrater reliability of the Positive and Negative Syndrome Scale for Schizophrenia (PANSS; German version). To our knowledge this is the first empirical report on interrater reliability and on results of rater training of the German version of the PANSS despite the widespread use of the scale. In a total of 47 training participants with different clinical experience standardized PANSS rater training was carried out and subsequently evaluated. Therefore, concordance rates with an expert standard (C) and weighted coefficients kappa (kappa W) were calculated. As a main outcome of the studies, at least 3 training sessions were necessary but also sufficient to reach acceptable interrater reliability of the PANSS (C > 80%, kw > 0.60). In training participants with low psychiatric experience the level of interrater reliability of schizophrenic negative symptoms did not reach the results of positive symptoms after the training. Despite some conceptual limitations with respect to negative symptoms, the German version of the PANSS seems highly suitable to assess a broad spectrum of schizophrenic psychopathology in a reliable and economic manner. The present results also underline the practicability of our recommendations for conducting PANSS rater training in the clinical and scientific field as part of quality control and quality assurance in psychopathological assessment.     

Interrater reliability of the Japanese version of the Positive and Negative Syndrome Scale and the appraisal of its training effect

The purpose of the present study is to test interrater reliability of the Japanese version of the Positive and Negative Syndrome Scale (PANSS) and to examine factors possibly affecting the reliability. The study group conducted the PANSS rating on 20 patients with DSM-IV schizophrenia. For the analysis of interrater reliability, intraclass correlation coefficient (ICC) was calculated. The ICC for individual items of the PANSS ranged from 0.26 to 0.92, and those for the positive, negative, and general psychopathology subscales were 0.85, 0.83 and 0.75, respectively. The Cronbach's alpha coefficient for the subscales were 0.84, 0.87 and 0.76, respectively. The interrater reliability and the internal consistency were satisfactory and similar to those obtained in the antecedent studies. No salient training effect was found in a sequential analysis of the concordance rate. It is concluded that the Japanese version of the PANSS is a reliable and efficient tool for comprehensive assessment of the schizophrenic syndrome.     

Multilevel ordinal factor analysis of the Positive and Negative Syndrome Scale (PANSS)

Clinical assessments of the presence and severity of psychopathology are often collected by health care professionals in mental health services or clinical researchers trained to use semi‐structured interviews. Clustering by interviewer or rater needs to be considered when performing psychometric analyses such as factor analysis or item response modelling as non‐independence of observations arises in these situations. We apply more suitable multilevel methods to analyse ordinally scored Positive and Negative Syndrome Scale (PANSS) items. Our aim is to highlight the differences in results that occur when the data are analysed using a hierarchically sensitive approach rather than using a traditional (aggregated) analysis. Our sample (n = 507) consisted of patients diagnosed with schizophrenia who participated in a multi‐centre randomized control clinical trial, the DIALOG study. Analyses reported and compared include an exploratory factor analysis as well as several recently published multifactor models re‐estimated within a confirmatory analysis framework. Our results show that the fit of the model and the parsimony of the exploratory factor analysis (EFA) models indicated by the number of factors necessary to explain the inter‐correlation among PANSS items improved significantly when data clustering is taken into account through multilevel analysis. Our modeling results support the pentagonal PANSS model first proposed by White et al. (1997). Copyright © 2014 John Wiley & Sons, Ltd.     

Use of NON-PARAMETRIC Item Response Theory to develop a shortened version of the Positive and Negative Syndrome Scale (PANSS)

Background

Nonparametric item response theory (IRT) was used to examine (a) the performance of the 30 Positive and Negative Syndrome Scale (PANSS) items and their options ((levels of severity), (b) the effectiveness of various subscales to discriminate among differences in symptom severity, and (c) the development of an abbreviated PANSS (Mini-PANSS) based on IRT and a method to link scores to the original PANSS.

Methods

Baseline PANSS scores from 7,187 patients with Schizophrenia or Schizoaffective disorder who were enrolled between 1995 and 2005 in psychopharmacology trials were obtained. Option characteristic curves (OCCs) and Item Characteristic Curves (ICCs) were constructed to examine the probability of rating each of seven options within each of 30 PANSS items as a function of subscale severity, and summed-score linking was applied to items selected for the Mini-PANSS.

Results

The majority of items forming the Positive and Negative subscales (i.e. 19 items) performed very well and discriminate better along symptom severity compared to the General Psychopathology subscale. Six of the seven Positive Symptom items, six of the seven Negative Symptom items, and seven out of the 16 General Psychopathology items were retained for inclusion in the Mini-PANSS. Summed score linking and linear interpolation was able to produce a translation table for comparing total subscale scores of the Mini-PANSS to total subscale scores on the original PANSS. Results show scores on the subscales of the Mini-PANSS can be linked to scores on the original PANSS subscales, with very little bias.

Conclusions

The study demonstrated the utility of non-parametric IRT in examining the item properties of the PANSS and to allow selection of items for an abbreviated PANSS scale. The comparisons between the 30-item PANSS and the Mini-PANSS revealed that the shorter version is comparable to the 30-item PANSS, but when applying IRT, the Mini-PANSS is also a good indicator of illness severity.     

The Factor Structure of the Anorexia Nervosa Inventory for Self-Rating in a population-based sample and derivation of a shortened form

The Anorexia Nervosa Inventory for Self-Rating (ANIS) was the first instrument covering aspects of the general psychopathology of eating disorders alongside eating attitudes, but its factorial integrity in non-clinical samples has not yet been investigated. Thus, this report is aimed at assessing the factorial structure of the ANIS with different methods of extraction and rotation. Data from a population-based random sample of German-speaking Italian schoolgirls aged 11–20 years (n = 1402) were used. The instruments included the ANIS and the Eating Behaviour Severity Scale. The internal consistency (Cronbach’s α of the ANIS and four of its subscales was 0.70– 0.88; however, reliability of the subscales “Sexual Anxieties” and “Obsessive–Compulsive Traits” was doubtful in non-clinical female adolescents. The original six factors were convincingly replicated by maximum likelihood extraction and principal component analysis. As some items and subscales showed weaknesses, a shortened 20-item version was derived containing the subscales “Figure Consciousness”, “Feelings of Inadequacy”, “Adverse Effects of Meals”, and “Bulimia”. All items showed factor loadings > 0.50 and item-total-correlations between 0.30 and 0.80. Internal consistency of the ANIS-20 total scale (0.90) was remarkable as it was for the subscales (0.70– 0.85); discriminant validity as assessed by a cross-validational approach (random split-half samples) was not affected by this abbreviation. In conclusion, both the original ANIS and the ANIS-20 are psychometrically sound instruments. Because brevity is important in screening studies, the short form is recommended. Received: 16 December 1996 / Accepted: 27 April 1998     

The Prudhoe Cognitive Function Test, a scale to assess cognitive function in adults with Down's syndrome: inter-rater and test–retest reliability

Background The Prudhoe Cognitive Function Test (PCFT) was designed to measure cognitive function in subjects with all degrees of intellectual disability (ID) and to be administered by non‐specialist raters. The aim of the present study was to measure the test–retest and inter‐rater reliability of the PCFT. Methods Three raters, one a specialist and two non‐specialists, administered the PCFT to 14 subjects with Down's syndrome on two occasions separated by 4 weeks. Results The intra‐class correlation coefficients (ICCs) between the rater pairs (n = 3) were 0.99, 0.99 and 0.98 (P < 0.01). Floor effects were recorded for two items. The ICC for test–retest reliability was 0.99 (P < 0.01). Conclusions The PCFT is a highly reliable instrument when used by either specialist or non‐specialist raters. It has excellent temporal stability.     

Quantifying peer interactions for research and clinical use: the Manchester Inventory for Playground Observation

Direct observation of peer relating is potentially a sensitive and ecologically valid measure of child social functioning, but there has been a lack of standardised methods. The Manchester Inventory for Playground Observation (MIPO) was developed as a practical yet rigorous assessment of this kind for 5-11 year olds. We report on the initial reliability and validity of the MIPO and its ability to distinguish social impairments within different psychopathologies.We observed 144 clinically referred children aged 5;00-11;11 (mean 8.8) years with Externalising (n = 44), Internalising (n = 19), Autism Spectrum Disorders (n = 39) or Specific Language Impairment (n = 42), and 44 class-controls, in naturalistic playground interaction. Observers, blind to clinical diagnosis, completed the MIPO and the teacher checklist from the Social Skills Rating System (SSRS).MIPO items showed high internal consistency (alpha = .924; all ‘alpha if item deleted’ values > .91), inter-observer reliability (mean κ_w = .77) and test-retest stability (over 2 weeks; mean κ_w = .58). MIPO totals showed convergence with SSRS (n = 68, r_s = .78, p < .01) and excellent discrimination between case and control (sensitivity = 0.75 and specificity = 0.88, AUC = .897). Externalising, Autistic Spectrum and Language Impaired groups showed distinct profiles of MIPO impairment consistent with theory:Internalising disorders less so. 65.3% of clinical cases were classified accurately for primary diagnosis.The MIPO shows reliability and validity as a measure of children's social functioning relevant in developmental research and as a clinical tool to aid differential diagnosis and intervention planning.     

Reliability of the Charcot‐Marie‐Tooth functional outcome measure

The CMT‐FOM is a 13‐item clinical outcome assessment (COA) that measures physical ability in adults with Charcot‐Marie‐Tooth disease (CMT). Test‐retest reliability, internal consistency and convergent validity have been established for the CMT‐FOM. This current study sought to establish inter‐rater reliability. Following an in‐person training of six international clinical evaluators we recruited 10 participants with genetically diagnosed CMT1A, (aged 18‐74 years, 6 female). Participants were evaluated using the CMT‐FOM over 2 days. Participants were given at least a 3 hour rest between evaluations, and were assessed twice each day. Following the provision of training by master trainers, all 13 items of the CMT‐FOM exhibited excellent inter‐rater reliability for raw scores (ICC_1,1 0.825‐0.989) and z‐scores (ICC_1,1 0.762‐0.969). Reliability of the CMT‐FOM total score was excellent (ICC_1,1 0.983, 95% CI 0.958‐0.995). The CMT‐FOM is a reliable COA used by clinical evaluators internationally. The next steps are to establish further validation through psychometric evaluation of the CMT‐FOM in the Accelerate Clinical Trials in CMT (ACT‐CMT) study.     

The rationale, development and reliability of a new screening psychiatric instrument

Background: This paper describes the rationale, development, reliability and validity of a new screening psychiatric instrument. Method: The instrument comprises 26 items that tap the cardinal features of main psychiatric categories as defined by ICD-10 and DSM-IV. These items were adapted from various structured and semi-structured diagnostic interviews that yield ICD-10 and DSM-IV psychiatric diagnoses. After a training course, 12 trainees and the trainer rated blindly the 26 items on 45 subjects (22 with psychopathology and 23 without). Inter-rater reliability coefficient (Kappa) was estimated between trainees and the trainer on each item of the instrument. The total score on the new instrument was then correlated with the total score on the Arabic Self Reporting Questionnaire (SRQ-20) and the Arabic version of the General Health Questionnaire (GHQ) in a random sample from the general population (n=365). Logistic regression was utilised to estimate the power of the total score on the new instrument in discriminating between cases and non-cases as classified by the SRQ-20. Results: Excellent levels of agreement (Kappa > 0.80) were found for all items except for obsession (Kappa = 0.65) and for depressed mood (Kappa = 0.70). Moderate correlations were found between the total score on the new instrument and total score on SRQ-20 (r = 0.69) and the total score on the Arabic GHQ (r = 0.7). The new instrument correctly classified 89% of subjects into cases and non-cases. Conclusions: The results of this study indicate that the new instrument is a highly reliable and valid screening instrument. The authors are now investigating its test-retest reliability and its procedural validity. Accepted: 6 November 1998     

Reliability of the ADI-R: Multiple Examiners Evaluate a Single Case

The authors assessed the reliability of the Autism Diagnostic Interview (ADI-R). Seven Clinical Examiners evaluated a three and one half year old female toddler suspected of being on the Autism Spectrum. Examiners showed agreement levels of 94–96% across all items, with weighted kappa (K_w) between .80 and .88. They were in 100% agreement on 74% of the items; in excellent agreement on 6% of the items (93–96%, with K_w between .78 and .85); in good agreement on 7% (89–90%, with K_w between .62 and 0.68); and in fair agreement on 3% (82 – 84%, with K_w between .40 and .47). For the remaining 10% of ADI-R items, examiners showed poor agreement (50–81% with K_w between −.67 and .37).     

A preliminary evaluation of the reliability and validity of a self‐reported communicative functioning item pool

Background: Item banking, an approach to test development based in item response theory (IRT), is beginning to be applied to the measurement of communicative functioning in aphasia. This approach involves calibrating a set of test items responding to a particular latent trait to a common measurement scale. One method for validating such scales is to examine the degree to which obtained item calibration estimates agree with a priori item rankings based on theory or expert opinion.

Aims: The purpose of this study was to evaluate the utility of magnitude estimation (ME) procedures for validating item banks containing self‐reported functional performance items, and to make a preliminary analysis of the validity of a proposed item pool for measuring self‐reported communicative functioning in aphasia.

Methods & Procedures: A total of 14 raters made ME ratings of physical and communicative functioning items. These ratings were evaluated for their intra and inter‐observer reliability and, for subsets of the items, their correspondence with previously published IRT calibration estimates was also evaluated.

Outcomes & Results: Intra‐rater reliability was moderate to high, and inter‐rater reliability was high. Correspondence with IRT calibrations was high for physical items, and moderate for communication items. The distribution of ME ratings for the communication items was negatively skewed.

Conclusions: ME procedures have utility for investigating the validity of functional performance items. The results suggest that communicative functioning may have a more complex latent structure than physical functioning, and that the proposed item pool might benefit from the inclusion of additional items at the lower end of the scale.     

Cross-cultural adaptation and validation of the Spanish version of the Calgary Depression Scale for Schizophrenia

BACKGROUND: The Calgary Depression Scale for Schizophrenia (CDSS) is a valid tool to assess depression in schizophrenics and has been translated, adapted, and validated to be used in different non-English languages. Therefore, it may be predicted that a Spanish version of this scale will be also a valid instrument to assess symptoms of depression in patients with schizophrenia. OBJECTIVE: We determined the validity of the Spanish version of the Calgary scale (CDSS-S). METHODS: Outpatients and inpatients (n=93) diagnosed as having schizophrenia by DSM-IV criteria confirmed by SCID-IV interview were included. The Positive and Negative Syndrome Scale (PANSS), Hamilton Depression Rating Scale (HDRS-17 and HDRS-21 items), Montgomery-Asberg Depression Rating Scale (MADRS), Extrapyramidal Symptoms Rating Scale (ESRS), and Barnes Acathisia Rating Scale were administered by a first rater, whereas the CDSS-S was assessed by a second independent rater. RESULTS: The internal consistency (Cronbach's alpha 0.83) and the interrater reliability (>0.73 intraclass correlation coefficient [ICC] for single items and 0.92 for total score) were good. The test-retest reliability was high (ICC of 0.89). The scale showed a good construct validity with statistically significant correlations with HDRS-17, HDRS-21, MADRS, and G6 item (depression) of PANSS. The CDSS showed no correlation with the positive subscale of PANSS and a weak correlation with the negative subscale, general psychopathology subscale, and total score of PANSS. A cut point of five showed 94.7% sensitivity, 86.5% specificity, and 70% and 98% positive and negative predictive values, respectively. CONCLUSIONS: The Spanish version of CDSS is a valid instrument to assess depressive episodes for stabilized and acute patients with schizophrenia.     

The Child and Adolescent Services Assessment: Interrater Reliability and Predictors of Rater Disagreement

The current study evaluated the interrater reliability of the Child and Adolescent Services Assessment (CASA), a widely used structured interview measuring pediatric mental health service use. Interviews (N?=?72) were randomly selected from a pediatric effectiveness trial, and audio was coded by an independent rater. Regressions were employed to identify predictors of rater disagreement. Interrater reliability was high for items (>?94%) and summary metrics (ICC?>?.79) across service sectors. Predictors of disagreement varied by domain; significant predictors indexed higher clinical severity or social disadvantage. Results support the CASA as a reliable and robust assessment of pediatric service use, but administrators should be alert when assessing vulnerable populations.     

Diffusion, perfusion, and T2 magnetic resonance imaging of anti-intercellular adhesion molecule 1 antibody treatment of transient middle cerebral artery occlusion in rat

The effect of anti-intercellular adhesion molecule-1 (anti-ICAM-1) antibody treatment of transient (2 h) middle cerebral artery (MCA) occlusion in the rat was measured using diffusion (DWI)-, T₂ (T2I)- and perfusion (PWI)-weighted magnetic resonance imaging. Rats were treated upon reperfusion with an anti-ICAM-1 monoclonal antibody (n=11) or a control antibody (n=7). DWI, T2I and PWI were performed before, during, and after induction of focal cerebral ischemia from 1 h to 7 days. In both groups, the apparent diffusion coefficient of water (ADC_w) and cerebral blood flow (CBF) values in the ischemic region significantly declined from the preischemic ADC_w values (p<0.05). The post ischemic increase in T₂ of the control group was significantly higher at 48 h than in the anti-ICAM-1 treated group (p<0.05). CBF was not significantly different between the two groups. The temporal profiles of MRI cluster analysis, which combines ADC_w and T₂ maps into a single image, was significantly different between groups. These data suggest that the neuroprotective effect of anti-ICAM-1 antibody treatment is reflected in reductions of T₂ and lesion growth during reperfusion and may not be associated with increased cerebral perfusion.     

Development of the Hypertonia Assessment Tool (HAT): a discriminative tool for hypertonia in children

Aim The aim of this study was to develop a tool to identify paediatric hypertonia subtypes. Method Items generated by experts were subscaled (spasticity, dystonia, rigidity). The tool was administered to 34 children (19 males, 15 females, mean age 8y 2mo, range 2y 5mo–18y 7mo) with hypertonia and cerebral palsy (CP) in Gross Motor Function Classification System (GMFCS) levels: I, n=7; II, n=5; III, n=7 level IV, n=7; and level V, n=8 level. Kuder–Richardson Formula 20 determined internal consistency. To assess reliability, two physicians administered the tool to 25 additional children with CP (15 males, 10 females; mean age 10y 8mo; GMFCS levels I, n=4; II, n=3; III, n=7; IV, n=4; and V, n=7) on two occasions, 2 weeks apart. To evaluate validity, a third physician diagnosed the hypertonia by neurological examination. Results The internal consistency of the spasticity items was moderate (α=0.58), and dystonia was high (α=0.79). Item reduction eliminated seven of the 14 original items. The agreement of the spasticity and rigidity subscales was adequate (prevalence‐adjusted bias‐adjusted kappa [PABAK] ranging from moderate [0.57] to excellent [1.0]) for validity, test–retest reliability, and interrater reliability. For dystonia agreement was lower, with PABAK ranging from fair (0.30) to good (0.65). Eighty‐seven per cent had spasticity and 78% had dystonia. Interpretation The Hypertonia Assessment Tool has good reliability and validity for identifying spasticity and the absence of rigidity, and moderate findings for dystonia.     

Burnout in direct care staff in intellectual disability services: a factor analytic study of the Maslach Burnout Inventory

Background There is gathering research interest in the well‐being of staff working in services for people with intellectual disability (ID), including the assessment of burnout and its correlates. However, no previous studies have considered the applicability of the main three dimensions of burnout to staff in ID services. Methods Data were analysed from two samples of staff (total n = 184) who participated in research studies that included completion of the Maslach Burnout Inventory (MBI). Results Nineteen of the MBI items loaded clearly onto factors closely resembling the three original subscales: emotional exhaustion, depersonalization and personal accomplishment. Internal consistency for the three MBI subscales was fair to good (range 0.68–0.87). Conclusions The original three MBI dimensions were found to be highly relevant to the present sample of staff. The analyses support the construct validity and reliability of the MBI for staff in ID services.     

Validation of the Spanish version of the Trunk Impairment Scale Version 2.0 (TIS 2.0) to assess dynamic sitting balance and coordination in post-stroke adult patients

Background: In recent years the Trunk Impairment Scale version 2.0 (TIS 2.0) has been a frequently used scale to assess dynamic sitting balance and trunk control for stroke patients. Objective: To translate the TIS 2.0 into Spanish and validate it as an instrument to evaluate dynamic sitting balance and trunk control and coordination for post-stroke adult patients. Methods: The original version was translated into Spanish and was agreed by a team of experts. A back-translation into English was subsequently performed and sent to the original author, who approved this version. 58 post-stroke patients’ performance was recorded on a videotape. These videos were then used to carry out four measurements to assess the intra-rater and inter-rater reliability, two of these were performed by the same rater and the third and fourth by a second and third rater. Results: The reliability was calculated by the Kappa index, and was superior to 0.80 for intra-rater reliability, while inter-rater reliability varied from 0.487 to 1. Cronbach’s alpha for internal consistency was 0.896 and to subscales dynamic sitting balance and coordination were 0.899 and 0.613 respectively. Intra-class correlations (ICC) for the summed scores of the different subscales were above 0.90 for all of them. Conclusion: The Spanish version of the TIS 2.0 is valid and reliable, and can be recommended for use in the evaluation of dynamic sitting balance and trunk control and coordination in future research on post-stroke patients. Guidelines for treatment and level of quality of trunk activity can be derived from its use.     

Improving the usefulness of the Karolinska Psychodynamic Profile in research: proposals from a reliability study

The interrater reliability of data obtained by use of the Karolinska Psychodynamic Profile (KAPP) was tested among 60 women seeking treatment for drinking problems. The first rater had a psychodynamic background but was minimally trained rating the KAPP subscales and performing KAPP interviews. Independent, blind ratings of audiotaped interviews by an experienced KAPP rater revealed that 8 of the subscales obtained satisfactory reliability, whereas 6 subscales showed unsatisfactory reliability. Furthermore, data for one subscale (normopathy) showed a zero correlation between raters, probably due to the novelty of the construct. Additionally 3 subscales related to bodily aspects were of little clinical significance among the present study group. Our data were compared with data from previous KAPP reliability studies, and the reasons for similarities and discrepancies of results are discussed.     

A preliminary examination of the validity and reliability of a new brief rating scale for symptom domains of psychosis: Brief Evaluation of Psychosis Symptom Domains (BE-PSD)

BackgroundBrief assessments have the potential to be widely adopted as outcome measures in research but also routine clinical practice. Existing brief rating scales that assess symptoms of schizophrenia or psychosis have a number of limitations including inability to capture five symptom domains of psychosis and a lack of clearly defined operational anchor points for scoring.MethodsWe developed a new brief rating scale for five symptom domains of psychosis with clearly defined operational anchor points – the Brief Evaluation of Psychosis Symptom Domains (BE-PSD). To examine the psychometric properties of the BE-PSD, fifty patients with schizophrenia or schizoaffective disorder were included in this preliminary cross-sectional study. To test the convergent and discriminant validity of the BE-PSD, correlational analyses were employed using the consensus Positive and Negative Syndrome Scale (PANSS) five-factor model. To examine the inter-rater reliability of the BE-PSD, single measures intraclass correlation coefficients (ICCs) were calculated for 11 patients.ResultsThe BE-PSD domain scores demonstrated high convergent validity with the corresponding PANSS factor score (r_s = 0.81–0.93) as well as good discriminant validity, as evidenced by lower correlations with the other PANSS factors (r_s = 0.23–0.62). The BE-PSD also demonstrated excellent inter-rater reliability for each of the domain scores and the total scores (ICC(2,1) = 0.79–0.96).ConclusionsThe present preliminary study found the BE-PSD measure to be valid and reliable; however, further studies are needed to establish the psychometric properties of the BE-PSD because of the limitations such as the small sample size and lacking data on test-retest reliability or sensitivity to change.